Putting that aside, it's true that Ubuntu has completely taken away the spotlight from other Linux distros, which runs counter to the anti-monoculture argument which was commonly thrown around in previous years by Linux... advocates. But even as a user of another distribution, I don't really mind.
Ubuntu and Canonical as figureheads in the Linux community make it a much more tangible alternative than the previous cloud of distributions recommended to everyone, with ever changing dominance. It's seen as a rival on par with the proprietary OSes and the fact that it's projected that image for four years now only strengthens the position of the entire lot.